An immersion nozzle of the type mentioned above is known from WO 98/53938. This immersion nozzle has a cylindrical shape with a circular, oval or bone-shaped cross section. The outlet opening is slit-shaped and extends continuously at the base and into the side wall of the cylindrical part of the immersion nozzle. With this construction of the immersion nozzle, a long useful life is achieved, as is guidance of the molten metal with little turbulence and a small penetration depth into the slab mold.
It is disadvantageous that the flow back to the casting surface is small in an immersion nozzle of this kind with slab widths above 1200 mm. This negatively affects casting slag formation because there is too little heat entering the casting surface due to insufficient flow and, therefore, inadequate supply of new hot molten metal into this area.